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1、1,NUTRITION ACROSS THE LIFE SPAN,Elderly,Adulthood,Adolescence,Pregnancy,Infancy,Childhood,Growth Development Maintenance of health Prevention of disease Treatment of disease Slowing down of aging process,Role of Diet & Nutrition,2,General Objectives,A) Demonstrate your understanding of how maternal
2、 physiological changes affect nutritional needs during pregnancy & lactation Demonstrate your understanding of special nutritional requirements pre- and during pregnancy and lactation Demonstrate your understanding of major nutritional concerns associated with pregnancy and lactation Propose meal pl
3、ans with adequate nutrients for a given pregnant or lactation woman,3,Specific Objectives,1) Explain physiological changes affecting nutritional needs changes in maternal physiology during pregnancy and lactation foetal growth and development maternal weight changes Explain the importance of nutriti
4、on before pregnancy Discuss special nutritional requirements for pregnancy and lactation energy, macronutrients, vitamins & minerals effects of maternal nutrition on milk volume and composition Outline various diet-related concerns associated with pregnancy heartburn, nausea, cravings, aversions Und
5、erstand the major nutritional concerns associated with lactation state the importance of preparatory support describe effects on maternal health Discuss the effects of lifestyle and environmental influences Plan meals with adequate nutrients according to the RDDA and dietary guidelines,4,Nutrition i
6、n Pregnancy,5,Stages of Pregnancy & Birth,Terms for Stages surrounding Pregnancy and Birth,PRECONCEPTION = before pregnancy PERICONCEPTION = 13 months before pregnancy to the first 6 weeks after delivery,37,6,Other Important Terminologies,gestation = period from conception to birth; for human beings
7、, gestation lasts from 38 - 42 weeks & is commonly divided into three periods called trimesters gestational age = stage of foetal growth & development at birth, varying from a premature delivery to full term or post term trimester = three 13-14 week periods into which normal pregnancy of 38-42 weeks
8、 is divided arbitrarily for purposes of discussion and analysis critical periods = finite periods during development in which certain events may occur that will have irreversible effects on later developmental stages,7,Physical Changes during Pregnancy,Cessation of monthly menstruation Abdomen protr
9、uding Breasts enlarge Weight gain Common swelling (edema), especially in the legs need to urinate more often and more urgently nausea and vomiting, particularly in the mornings (morning sickness), heartburn constipation backache in varying degrees,8,Physiological Changes during Pregnancy,Endocrine B
10、ody composition Blood volume & composition Metabolism Cardiovascular Respiration Kidney Gastrointestinal,Why do these changes occur? to regulate maternal /fetal metabolism & waste removal to promote foetal growth (supply nutrients & oxygen ) to prepare mother for labour & lactation,9,1) Endocrine,Th
11、e placenta forms large quantities of Human chorionic gonadotropin prevent degeneration of corpus luteum, causes it to secrete large amounts of estrogen & progesterone. Effects prevent menstruation, endometrium grows and stores large amounts of nutrients Estrogen enlargement of uterus, enlargement of
12、 breast & growth of breast ductal structure, relaxes pelvic ligaments easier passage of fetus through birth canal Progesterone development of uterine endometrium, prevent uterine contractions, helps estrogen prepare breast for lactation Human chorionic somatomammotropin decrease utilization of gluco
13、se by mother (make large quantities available to fetus), release free fatty acids from maternal fat stores,10,An average weight gain of 12.5 kg in a typical 40 week pregnancy amounts to approximately 20% increase in body weight Most weight gain occurs in the last 20 weeks of pregnancy 40% weight gai
14、n fetus, placenta, amniotic fluid 60% maternal (6-8 kg) increased fluid volume, protein deposition and fat stores (due to increased mammary, uterine, kidney, heart tissue volume, increase in total fluid volume and body fat). About 1/3 of weight gain (3-6 kg) is fat,2) Body Composition,11,45-50% incr
15、ease in blood volume (hypervolemia) Needed to provide for extra blood flow to the uterus, extra metabolic needs of the fetus, increased perfusion of other organs esp kidneys Smaller increase in other blood components (e.g. RBC, blood proteins, lipids, enzymes) compared to increase in plasma volume h
16、emodilution “physiologic anaemia of pregnancy” Iron supplementation modifies but does not obliterate the usual fall in Hb and Hct Erythropoiesis (production of RBC in the marrows) need more dietary iron, micronutrients (e.g. folate, zinc),3) Blood Volume & Composition,12,4) Metabolic, BMR 15% in lat
17、er half of pregnancy. Mother frequently has sensations of becoming overheated Due to tissues actively synthesised in the foetus and associated supportive structures Due to extra load, greater amounts of energy is expended during muscle activity Major source of fuel for maternal tissue : FAT Major source of fetal energy : GLUCOSE Thus, Maternal fat use to free glucose for foetus Maternal lipolysis during 3rd trimester Maternal glucose levels fall as foetal demands ,
